The present disclosure relates to gas turbine engines, and more particularly to an exhaust duct therefor.
Gas turbine engines, such as those which power modern military aircraft, include a compressor section to pressurize a supply of air, a combustor section to burn a hydrocarbon fuel in the presence of the pressurized air, and a turbine section to extract energy from the resultant combustion gases and generate thrust. Downstream of the turbine section, an augmentor section, or “afterburner”, is operable to selectively increase the thrust. The increase in thrust is produced when oxygen contained within the exhaust gases of the engine downstream of the turbine section is injected with fuel and burned to generate a second combustion.
Due in part to the harsh environment of the second combustion, a liner assembly is disposed between the exhaust gas and the exhaust duct. These may be of single or double walled construction, with a hot sheet and a cold sheet. Cooling air typically sourced from a fan section is flowed between the liner assembly and exhaust duct then discharged through the liner assembly.
The attachment of the hot sheet and the cold sheet is typically accomplished with Z-band structural supports which, along with baffles fitted transverse thereto control the flow pressures within the exhaust duct. As engine pressures vary axially and circumferentially in non-axisymmetric systems, the exhaust duct is partitioned both axially and circumferentially. The baffles fit within slots in the Z-band structural supports and, although effective, may rub against the Z-band structural supports which may cause wear from the high acoustic environment. Furthermore, the Z-band structural supports and baffles may not be readily applicable to non-axisymmetric exhaust ducts.